T-square and other drafting device.



v. A. RIGAUMONT.

T-SQUARE AND OTHER DRAFTING DEVICE.

APPLICATION FILED MAR.3, 1911.

1,029,225, Patented June 11, 1912.

Fig 3.

' WITNESSES v mvzm'on COLUMBIA PLANDURAPH c0. WASHINGTON, D. c.

VICTOR ALBERT BIGAUMONT, OF PITTSBURGH, PENNSYLVANIA.

T-SQUARE AND OTHER DBAFTING DEVICE.

Specification of Letters Patent.

Application filed March 3, 1911.

Patented June 11, 1912.

Serial No. 611,964.

To all whom it may concern:

Be it known that I, VIo'roR ALBERT RIeAUMoNT, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in T-Squares and other Drafting Devices, (Case 1,) of which the following is a specification.

This invention relates to drafting implements such as T squares, triangles, straight edges, irregular curves and like implements which are used as a guide for the pen.

The object of the invention is to provide an implement of this character which prevents the ink from flowing or being drawn underneath the edge of the implement, but which nevertheless presents a broad square edge for guiding the pen.

Draftsmen frequently experience annoyance and delay in their work on account of the ink being drawn out of the pen and flowing by capillary attraction underneath the edge of the T-square, triangle, straight edge or irregular curve, and producing a blot which not only mars the work but requires considerable time to correct. This is due frequently to minute particles of dirt, dust, or lint or irregularity in the surface of the paper, and sometimes to the fact that the pen is guided too close against the vertical edge of the T square or other implement. This difiiculty leads many draftsmen to hold their pens slightly inclined, that is bearing against the upper port-ion of the Vertical edge of the T square or other implement, but out of contact with the lower portion of said vertical edge. The latter expedient leads to more or less irregularity in the work as it is impossible to always keep the pen at exactly the same inclination. The most accurate work is of course produced when the pen is held squarely against the vertical edge of the T square or other implement, but this, as above stated, is likely to cause the ink to be drawn from the pen by capillary attraction underneath the edge of the T square or other implement and produce blots as above stated.

The purpose of the present invention is to provide a T square, triangle, straight edge, irregular curve or like drafting implement which is so constructed that the foregoing difficulties are overcome. To this end the pen guiding edges of such implements have their corners at the surface which is in contact with the paper upon which the drawing is being made, cut away, preferably somewhat grooved, so that if the ink is drawn out of the pen it will gather in the slight gutter or cutaway portion and not be drawn underneath the im plement to produce a blot on the paper.

In the accompanying drawing, Figure 1 is an inverted plan view of a T-square embodying the invention; Fig. 2 is a cross section on an enlarged scale on theline 2-2, Fig. 1; Fig. 3 is a plan View of a triangle embodying the invention; and Fig. 4 is a cross section on the line 7-7, Fig. 3.

In the drawing the numeral 1 indicates the head of the T-square and 2 the blade thereof. The lower face of the blade adjacent to both edges is provided with a channel or groove 3 which, as shown in Fig. 2, is so located and shaped as to leave at the edge a downwardly projecting bead or rib 7, which extends into fairly close proximity to the plane of the lower face of said blade so as to leave a comparatively Wide square pen guiding edge. The bead or rib causes any ink which may be drawn from the pen by reason of contact of the pen with the edge of the T-square to gather on said rib. The groove inside of said rib is of material depth so that the ink cannot flow upwardly in said groove and then down on its opposite wall and consequently cannot get underneath the blade of the implement. The blade of the T-square nevertheless has a wide square vertical edge which forms a good guide for the pen so that the latter can be held in true vertical position in contact with said edge from top to bottom. Consequently very accurate work can be produced while at the same time the groove just inside of the lower corner does not permit any ink which may flow or be drawn out of the pen from getting underneath the implement and produce blots as with the old form of implement. Any ink which is drawn from the pen merely gathers in the groove from which it can readily be wiped. The groove extends only a short distance horizontally or inwardly from the pen guiding edge so that the breadth of the flat lower face of the implement is only slightly reduced by said grooves. Consequently there is no danger of the implement tipping in case considerable pressure is brought adjacent to either edge thereof.

The principle described is applicable to which serves as a pen guide, such as a T- I square, triangle, straight edge, irregular curve and the like. Triangles and irregular curves are used either side up and consequently With such instruments the grooves 3 areformed on both faces of such implements and also around the openings 10 in triangles as shown in Figs. 3 and 4.

The improvement described practically adds nothing or at least very little, to the cost of manufacture, andat'the same time prevents very considerable loss of time necessary for correcting drawings on account of blots thereon caused as heretofore stated.

What I claim is:

A drafting implement of the character described, comprising a blade or the like having flat top and bottom faces and square pen guiding edges, the bottom face being provided at each edge thereof With a groove spaced back from the edge and opening on the edge face in a manner to provide an overhanging lip projecting'into close proximity to the plane of a bottom face and leave a square pen guiding edge of only slightly less Width than the thickness of the blade, the bottom face of the blade between said grooves being an uninterrupted surface.

In testimony whereof, I have hereunto set my hand.

VICTOR ALBERT RIGAUMONT.

Witnesses:

F. W. WINTER, MARY E. CAIEVIOON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

